This disclosure relates to bin sweeps for moving and clearing grain and other stored materials from silos, grain bins and similar storage units. Specifically, this invention relates to a weight-sensitive link that connects an auger section of the bin sweep to a tractor drive unit or other floor support.
A grain bin sweep is generally found at the bottom of a grain bin having a flat floor. Typically, the grain bin has a circular horizontal cross-section. Diameters of grain bins vary from several feet to over one hundred feet. A bin sweep typically covers at least a portion of the radius of the bin, so that it sweeps a circular area of the bin as it rotates about an axis in the center of the grain bin.
To remove the stored material from a grain bin, a central opening at the bottom of the grain bin is opened to allow the grain to flow through by gravity. The grain flows like a viscous fluid much like the sand in an hourglass. Grain will flow into the floor opening until flow from gravity stops, leaving grain at the sides of the bin resting at an angle of repose. Additional openings spaced linearly from the center opening to the wall are opened, forming a trench-like valley. This allows access into the bin through a bin access door and removes the majority of the grain covering the bin sweep. The grain remaining in the bin must be removed. The bin sweep in a grain bin conveys the remaining grain or other stored material to the central floor opening.
A bin sweep typically includes a sweep arm having an auger that rotates about a horizontal axis for conveying grain that is lying on the floor of the grain bin toward the central floor opening or sump. The auger of the bin sweep extends radially outward from the center of the bin and is mounted adjacent to the central opening, usually through a connection that allows the bin sweep to pivot around an axis at the central floor opening. The bin sweep conveys grain toward the central floor opening as it gradually travels on an angular path within the grain bin. In some cases, the sweep is lengthened on subsequent passes to reach the circumference of the bin, eventually traveling over the entire floor surface of the grain bin.
A power source such as an electric or hydraulic motor is mounted to the central structure for supplying rotational power to the auger. Additionally, a driving means is typically used with the bin sweep for propelling the auger section about the central opening in the floor. The sweep drive mechanisms commonly include wheels or a track drive that will establish traction on the floor of the grain bin and is sometimes referred to as a tractor drive unit.
Present bin sweeps require an operator to enter the bin and lower the bin sweep onto the floor or place portions of the bin sweep (e.g., its support frame) on blocking before filling the bin with grain or other stored material. When supported by the floor or blocking, components of the bin sweep (such as the wheels, axles, connective brackets, etc.) are less likely to be damaged by the weight the stored material bearing down upon the bin sweep. Without such preventive measures, the floor support wheels of the bin sweep may indent into the floor, the wheels may permanently deform, or other structural damage may result.
However, after a bulk of the storage material has been removed, the bin sweep must be engaged to convey the remaining grain toward the center floor opening. To move relative to the floor surface, the bin sweep must be placed in an operating position, (i.e., be raised to provide a clearance between the floor surface and the rotating auger). A typical clearance between a back stop of a bin sweep and the floor is approximately one inch to two inches. Such clearance may be increased in particular locations due to floor unevenness. Consequently, the operator needs to enter the bin after some but not all of the grain has been drawn through the gravity outlets in order to raise the bin sweep into the operating position (such as by actuating a jack) or remove the blocking. This entry exposes the operator to possible grain engulfment.